CONSTITUTIONAL COMPOSITION AND ALLELOPATHIC POTENTIAL OF JAMAN (Syzygium cumini) LEAVES AGAINST CANARY GRASS AND WHEAT

Excessive use of herbicides in the crop field threatens the environment by destroying flora and fauna. Allelopathic substances might be proved as a substitute of chemical herbicides to suppress the target plants. In this study the Jaman (Syzygium cumini) leaves were extracted with H2O for its constitutional composition and then its allelopathic effects were investigated against pre- and post-germinated wheat and canary grass. By HPLC, total eight components were identified by comparing the chromatograms of the unknown with standard ones. The pre- and post-germinated bioassays were taken into consideration for wheat and canary grass separately. The results showed that over all 70% aqueous methanol extract of jaman leaves (2.5%-10%) increased the length of shoot and root linearly for both pre-germinated wheat bioassays (11.00-15.75 cm and 9.50-10.75) and post germinated wheat bioassays 14.50—17.00 cm and 10.35—12.75 cm, respectively) as compared with control ones. Similarly allelochemicals of jaman leaves depressed both the pre-germinated and post-germinated bioassays of canary grass as compared with control ones (6.75 - 1.75 cm and 4.25—0.90 cm for shoot and 4.00-0.45 cm and 1.85—0.30 cm for root, respectively). These results reveal that growth inhibition components may be present in the Jaman (Syzygium cumini) leaves and also certain components may be responsible for the allelopathic potential. Therefore, leaves of the titled plant may provide a possible material for the isolation and identification of allelopathic substances and may be helpful for the development of new natural herbicides